Mammalian bodies are highly dependent on sodium and chloride for their effective operation and these substances are arguably two of the three most important macronutrients the human body needs, the third being potassium.. Mammals use sodium and chloride to create our digestive juices, activate digestive enzymes, maintain the alkalinity of the immune system, regulate osmotic pressure, regulate the acid-base balance, and facilitate the absorption of glucose and most amino acids from the small intestine. Mammalian respiratory systems are based on “the chloride shift” and magnesium absorption requires sufficient availability of sodium.
The importance of sodium to the human, while not commonly understood, is demonstrated by level of ingenuity developed in the human autonomous systems (for which i have coined the acronym HAS) to control VERY PRECISELY the concentration of sodium in the blood and lymph systems, which hold about eighty five percent of total bodily sodium. In the event of salt deprivation, the adrenal glands produce aldosterone, which inhibits the secretion of sodium by the kidneys, and increases the production of RENIN, a compound which traps sodium in blood at the expense of increased blood viscosity. Moreover, plasma viscosity (the viscosity of the noncellular matrix of the blood). is highly dependent upon hydration status which, in turn, is dependent upon the availabilty of salt. Research published in the journal Aviation, Space, and Environmental Medicine demonstrated that dehydration increases systolic blood viscosity by 9.3% and diastolic blood viscosity by 12.5%. (http://www.townsendletter.com/Jan2012/measureblood0112.html). An increase in blood viscosity will make blood more difficult to pump around the system…a phenomenon well known to civil engineers.
So important is salt to humans that our taste buds are specifically designed to detect its presence in our food https://en.wikipedia.org/wiki/Taste. So important is salt to the human that the insertion of an isotonic saline drip is the single most common invasive procedure in modern hospitals, without which the number of fatalities would rise dramatically http://www.woundsresearch.com/article/9006 ,
The precision of the HAS in this task is even more remarkable. Sodium levels are controlled more precisely than any other substance at a concentration of between 135 and 145 mmol/L, an equivalent salt content of 8.2 gms per litre. A serum concentration above 145mmol/L is called HYPERCHLORIDIA and is a condition so rare that no local general practitioner will ever come across such a case. On the other hand, serum concentrations below 135 mmol/L, a condition known as Hyponatraemia, is well known to occur when people on restricted salt intakes drink too much fluid. This condition results in death in most cases.
Unlike sodium, however, the importance of chloride to the human is far less well documented. In fact, at the time of typing this note, 12 July 2015, there has NEVER been a medical study undertaken to establish the optimum levels of chloride intake for maximising human health. This is quite different to the world of veterinary science, where many, many studies have confirmed the benefits of ensuring high levels of chloride intake into to mammalian diets. Given that chloride is required by the human body to undertake the most fundamental aspects of living, namely breathing and eating, it is breathtaking that humans are being advised to restrict the intake of salt, still the only practical source of chloride in the human food supply chain.
Clearly, there can be no semantic argument that “too much” sodium is bad for ones health, as by definition, “too much” means more than is healthy. The question simply becomes “how much salt is too much?” On every practical measure, populations which have higher levels of salt consumption are associated with better health outcomes on a population basis. For example, the famous “Intersalt Study” contains a graph which clearly observes that the higher the level of salt consumed by the occupants of a particular country, the higher the life expectancy of those occupants is. There is no question that many millions of people are living abundantly healthy, active and long lives on salt intakes in excess of 20 grams per day. In japan, there are more than 58,000 people over the age of 100 living in Japan as I type. Of the 500 or so people that are older than 120 years of age, more than half of them live in Japan. Although the amount of salt in Japanese diets is now reducing, these centenarians had such high levels in their salt during the 1960’s that Lillian Gliebman wrote “An average of 27 grams of salt are excreted per day by farmers in Akita, and maximum values of 50-61 grams per day have been reported in this region” (Gleibermann 1973) and http://www.japantimes.co.jp/news/2014/09/15/national/japans-population-centenarians-continues-grow/#.VZD2aaSH4tw.
The USA, with nearly 3 times the population, has 53,364 centenarians… which means that people living in Japan have 3 times the chance of reaching 100 compared to people living in America. We know it isn’t genetic because people of Japanese descent living in the USA have the same health outcomes as all other Americans. Moreover, cancer rates, bone fracture rates and numerous other health measure in Japan are well below US rates, especially for women. The typical response to these differences are genes, fish and yadder. For the sake of the arguement, lets just accept this. We are still forced to conclude that the higher salt intake in Japan cannot be proven to reduce life expectancy and quality.
The original “Gatorade”, a sports drink which had salt as its main component, was the secret weapon in 1950’s basketball that resulted in one of the most famous of all sporting triumphs. The most common medical intervention in any hospital in any part of the world is the insertion of a saline (salt) drip into the veins of the patients and without this procedure, mortality rates in hospitals greatly increase.
The covenant between man and The Creator, according to the Old Testament, is sealed with salt. That same text tells us that God specifically requested that offerings to The Almighty be well seasoned with salt. People of great worth and reliability were once described as “the salt of the earth”. The word “soldier” came about because the Romans paid their Centurions with salt. The word salary has the same derivation. To be worth your salt was great praise. When I was a child, my father, a merchant mariner, would always make sure I had plenty of salt in my diet (in later life he stayed away from salt on medical advice.. and enjoyed poor health thereafter). Up until the widespread introduction of refrigeration, the average Anglo-Saxon took in half an ounce of salt every day and the US Army ration of salt up to and including WW2 was just over half an ounce each day. USArmy1942 . At the time of writing, the Israeli Defence Force continues to mandate that it’s personnel have a ration of 15+ grams of salt each and every day.
Despite our total dependence upon adequate levels of salt in our bodies to maintain our life function, we are told by the various public health authorities that salt is bad for us and that we should restrict our salt intake to as low 5gms per day (WHO and VicHealth for example). One would expect, prior to issuing this advice, that these bodies would have a substantial evidence based case which clearly establishes that lowering salt intakes to these levels would result in improved health and life expectancy outcomes. In fact, An eight-year study of a New York City hypertensive population stratified for sodium intake levels found those on low-salt diets had more than four times as many heart attacks as those on normal-sodium diets; the exact opposite of what the salt hypothesis would have predicted. (1995). Dr. Jeffrey R. Cutler documented no health outcomes benefits of lower-sodium diets.
Nearly all the arguments for encouraging the restriction of salt intake are similar to that issued by VicHealth, viz “Salt is made up of sodium and chloride and people are eating too much sodium in the form of salt, which is bad for health. Too much sodium increases the risk of high blood pressure, which is a leading cause of death and disability in Victoria (Lim, SS et al. 2012).”. There are several logical fallacies being deployed in example quoted above. Firstly, the link is only between sodium and high blood pressure, and even that link only occurs in “salt sensitive” people. Unsurprisingly, only people on restricted salt intakes are “salt sensitive”… i.e. they will experience an increase in blood pressure when they add salt to their food. a direct link between salt intake and death and disability has NOT been found and is NOT mentioned. Secondly, the topic of chloride adequacy is completely ignored. Thirdly, the most common side effect of reducing salt intake is for the body to increase RENIN production, thicken the blood and thereby increase the pressures at which the heart must operate at in order to circulate the blood.
My final point in this discussion relates to the Yanomami Indians, who dwell in Amazonian Brazil. These people are famous in salt hypertension studies because they have no salt in their diet and they have very low blood pressures. These people have an average lifespan of 29 years.
If you are interested, my first note on this topic, written in 2014, can be found at http://www.big-lies.org/salt